This invention relates generally to the use of gel sealants for environmentally sealable enclosures and, more particularly, to an environmentally sealable enclosure or assembly having a visual indicator for determining that the gel has formed a seal.
Protection of panels, boxes, cases, or other enclosures is often required when they are employed in wet environments, for example in humid conditions or underwater, where moisture or water can enter the enclosure or in contaminated environments where gases or airborne particles can enter the enclosure. Items such as electrical connections, electrical boxes, electrical panels, or in non-electrical applications such as jewel cases, or other applications where sensitive items or equipment are in use, all benefit from environmental sealing.
Normally, such protection is provided by the use of seals including O rings or gaskets to protect against moisture, dirt, or particle ingress. Such seals often do not function effectively due to enclosures fabricated with loose tolerances, poor surface finishes, or warped parts all of which hinder the formation of a proper seal. A proper seal is also hindered by the lack of proper mechanical loading of the assembly. Too little mechanical loading will not compress the O rings or gaskets enough to form a seal while too much mechanical loading can create bulges in the O rings or gasket allowing leakage in the seal. Further, such sealing devices do not provide a visual indication of the proper seal formation or the lack of a seal to the operator.
Because of their extremely soft and compliant nature, gels are particularly suited for sealing enclosures and their use is known in the art. The benefit of using gels to seal enclosures is even more apparent for sealing enclosures fabricated with loose tolerances and poor surface finishes, or warped parts, all of which can be found in parts made from injected molded plastic. Unlike an O ring or a gasket, a gel can form a seal under the application of a very low compressive force. Unfortunately, the use of a low compressive force with an O ring or gasket provides little or no feedback to the operator of whether a seal is properly formed or not. A gel can also form a seal under high compressive forces.
The current use of gels does not allow any visual feedback to the operator or anyone else of whether or not a seal is properly formed. An indication of whether or not a seal is formed is especially important for the use of gels because their tacky nature makes them prone to picking up surface contaminates such as dirt, sand, or other particles. Such surface contaminates can prohibit the formation of a proper seal between the gel and the mating part.
In accordance with a first aspect of the invention, a sealable enclosure is provided, the enclosure including a base and a cover attachable to the base. The base and cover have respective mating surfaces, wherein the base and cover form a chamber there between when the cover is attached to the base. A compliant gel sealant is disposed on the mating surface of one of the base and cover for environmentally sealing the chamber, with a visual indicator provided for determining that the chamber is sealed.
By way of non-limiting example, the visual indicator may comprise a non-opaque window formed in the cover, and a non-opaque tongue extending from the mating surface of the cover, the tongue aligned with the window such that a line of sight is provided through the respective window and tongue. The gel sealant is preferably disposed in a mating groove located about a perimeter of the mating surface of the base and substantially aligned with the tongue when the cover is attached to the base. In this manner, a wetted contact between the gel and a distal end of the tongue, indicating that an environmental seal is formed there between, is visible through the line of sight.
In accordance with a further aspect of the invention, a sealable assembly is provided, the assembly including a fixed surface defining an opening, a compliant gel sealant disposed about the opening. The assembly further includes a cover attachable to the fixed surface so as to form a substantially moisture-tight seal between the interior cover surface and the gel, the cover providing a visual indication of whether or not a seal is formed by the gel.
As will be apparent to those skilled in the art, other and further aspects of the present invention will appear hereinafter.